Internet Assigned Numbers Authority

Service Name and Transport Protocol Port Number Registry

Last Updated
2024-12-06
Expert(s)
TCP/UDP: Joe Touch; Eliot Lear, Kumiko Ono, Wes Eddy, Brian Trammell, 
Jana Iyengar, and Michael Scharf
SCTP: Michael Tuexen
DCCP: Eddie Kohler and Yoshifumi Nishida
Reference
[RFC6335]
Note
Service names and port numbers are used to distinguish between different
services that run over transport protocols such as TCP, UDP, DCCP, and
SCTP.

Service names are assigned on a first-come, first-served process, as
documented in [RFC6335].

Port numbers are assigned in various ways, based on three ranges: System
Ports (0-1023), User Ports (1024-49151), and the Dynamic and/or Private
Ports (49152-65535); the different uses of these ranges are described in
[RFC6335]. According to Section 8.1.2 of [RFC6335], System Ports are 
assigned by the "IETF Review" or "IESG Approval" procedures described in 
[RFC8126]. User Ports are assigned by IANA using the "IETF Review" process, 
the "IESG Approval" process, or the "Expert Review" process, as per 
[RFC6335]. Dynamic Ports are not assigned.

The registration procedures for service names and port numbers are
described in [RFC6335].

Assigned ports both System and User ports SHOULD NOT be used without
or prior to IANA registration.

************************************************************************
* PLEASE NOTE THE FOLLOWING:                                           *
*                                                                      *
* ASSIGNMENT OF A PORT NUMBER DOES NOT IN ANY WAY IMPLY AN             *
* ENDORSEMENT OF AN APPLICATION OR PRODUCT, AND THE FACT THAT NETWORK  *
* TRAFFIC IS FLOWING TO OR FROM A REGISTERED PORT DOES NOT MEAN THAT   *
* IT IS "GOOD" TRAFFIC, NOR THAT IT NECESSARILY CORRESPONDS TO THE     *
* ASSIGNED SERVICE. FIREWALL AND SYSTEM ADMINISTRATORS SHOULD          *
* CHOOSE HOW TO CONFIGURE THEIR SYSTEMS BASED ON THEIR KNOWLEDGE OF    *
* THE TRAFFIC IN QUESTION, NOT WHETHER THERE IS A PORT NUMBER          *
* REGISTERED OR NOT.                                                   *
************************************************************************

Request an Assignment
  [https://www.iana.org/protocols/apply]

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Service Name Port Number Transport Protocol Description Assignee Contact Registration Date Modification Date Reference Service Code Unauthorized Use Reported Assignment Notes
ssh 22 tcp The Secure Shell (SSH) Protocol [RFC4251] Defined TXT keys: u=<username> p=<password>
ssh 22 udp The Secure Shell (SSH) Protocol [RFC4251] Defined TXT keys: u=<username> p=<password>
smtp 25 tcp Simple Mail Transfer [IESG] [IETF_Chair] 2017-06-05 [RFC5321]
smtp 25 udp Simple Mail Transfer [IESG] [IETF_Chair] 2017-06-05 [RFC5321]
locus-map 125 tcp Locus PC-Interface Net Map Ser [Eric_Peterson] [Eric_Peterson]
locus-map 125 udp Locus PC-Interface Net Map Ser [Eric_Peterson] [Eric_Peterson]
225-241 Reserved [Jon_Postel] [Jon_Postel]
249-255 Reserved [Jon_Postel] [Jon_Postel]
rap 256 tcp RAP [J_S_Greenfield] [J_S_Greenfield]
rap 256 udp RAP [J_S_Greenfield] [J_S_Greenfield]
set 257 tcp Secure Electronic Transaction [Donald_Eastlake] [Donald_Eastlake]
set 257 udp Secure Electronic Transaction [Donald_Eastlake] [Donald_Eastlake]
258 Unassigned 2006-09-13
esro-gen 259 tcp Efficient Short Remote Operations [Mohsen_Banan] [Mohsen_Banan]
esro-gen 259 udp Efficient Short Remote Operations [Mohsen_Banan] [Mohsen_Banan]
325-332 Unassigned
icad-el 425 tcp ICAD [Larry_Stone] [Larry_Stone]
icad-el 425 udp ICAD [Larry_Stone] [Larry_Stone]
timed 525 tcp timeserver
timed 525 udp timeserver
dec-dlm 625 tcp DEC DLM

IANA assigned this well-formed service name as a replacement for "dec_dlm".
[Rudi_Martin_2] [Rudi_Martin_2]
dec_dlm 625 tcp DEC DLM [Rudi_Martin_2] [Rudi_Martin_2] This entry is an alias to "dec-dlm". This entry is now historic, not usable for use with many common service discovery mechanisms.
dec-dlm 625 udp DEC DLM

IANA assigned this well-formed service name as a replacement for "dec_dlm".
[Rudi_Martin_2] [Rudi_Martin_2]
dec_dlm 625 udp DEC DLM [Rudi_Martin_2] [Rudi_Martin_2] This entry is an alias to "dec-dlm". This entry is now historic, not usable for use with many common service discovery mechanisms.
domain-s 853 udp DNS query-response protocol run over DTLS or QUIC [IESG] [IETF_Chair] 2015-10-08 2022-04-01 [RFC7858][RFC8094][RFC9250]
blackjack 1025 tcp network blackjack
blackjack 1025 udp network blackjack
hpvmmagent 1125 tcp HP VMM Agent
hpvmmagent 1125 udp HP VMM Agent
slinkysearch 1225 tcp SLINKYSEARCH [Desmond_Chan] [Desmond_Chan]
slinkysearch 1225 udp SLINKYSEARCH [Desmond_Chan] [Desmond_Chan]
swldy-sias 1250 tcp swldy-sias [Peter_E_Williams] [Peter_E_Williams]
swldy-sias 1250 udp swldy-sias [Peter_E_Williams] [Peter_E_Williams]
servergraph 1251 tcp servergraph [Lindsay_Morris] [Lindsay_Morris]
servergraph 1251 udp servergraph [Lindsay_Morris] [Lindsay_Morris]
bspne-pcc 1252 tcp bspne-pcc
bspne-pcc 1252 udp bspne-pcc
q55-pcc 1253 tcp q55-pcc [Prem_Tirilok] [Prem_Tirilok]
q55-pcc 1253 udp q55-pcc [Prem_Tirilok] [Prem_Tirilok]
de-noc 1254 tcp de-noc
de-noc 1254 udp de-noc
de-cache-query 1255 tcp de-cache-query
de-cache-query 1255 udp de-cache-query
de-server 1256 tcp de-server [Jeff_Burdette] [Jeff_Burdette]
de-server 1256 udp de-server [Jeff_Burdette] [Jeff_Burdette]
shockwave2 1257 tcp Shockwave 2 [Dave_Simmons] [Dave_Simmons]
shockwave2 1257 udp Shockwave 2 [Dave_Simmons] [Dave_Simmons]
opennl 1258 tcp Open Network Library [Phil_Frisbie] [Phil_Frisbie]
opennl 1258 udp Open Network Library [Phil_Frisbie] [Phil_Frisbie]
opennl-voice 1259 tcp Open Network Library Voice [Phil_Frisbie] [Phil_Frisbie]
opennl-voice 1259 udp Open Network Library Voice [Phil_Frisbie] [Phil_Frisbie]
dx-instrument 1325 tcp DX-Instrument [Walt_Modic] [Walt_Modic]
dx-instrument 1325 udp DX-Instrument [Walt_Modic] [Walt_Modic]
zion-lm 1425 tcp Zion Software License Manager [David_Ferrero] [David_Ferrero]
zion-lm 1425 udp Zion Software License Manager [David_Ferrero] [David_Ferrero]
eicon-x25 1439 tcp Eicon X25/SNA Gateway
eicon-x25 1439 udp Eicon X25/SNA Gateway
orasrv 1525 tcp oracle
orasrv 1525 udp oracle
prospero-np 1525 tcp Prospero Directory Service non-priv
prospero-np 1525 udp Prospero Directory Service non-priv
svs-omagent 1625 tcp svs-omagent [Alberto_Berlen] [Alberto_Berlen]
svs-omagent 1625 udp svs-omagent [Alberto_Berlen] [Alberto_Berlen]
iden-ralp 1725 tcp iden-ralp [Chris_Stanaway] [Chris_Stanaway]
iden-ralp 1725 udp iden-ralp [Chris_Stanaway] [Chris_Stanaway]
direcpc-video 1825 tcp DirecPC Video [Chris_Kerrigan] [Chris_Kerrigan]
direcpc-video 1825 udp DirecPC Video [Chris_Kerrigan] [Chris_Kerrigan]
discovery-port 1925 tcp Surrogate Discovery Port [Keith_Thompson] [Keith_Thompson]
discovery-port 1925 udp Surrogate Discovery Port [Keith_Thompson] [Keith_Thompson]
x25-svc-port 1998 tcp cisco X.25 service (XOT)
x25-svc-port 1998 udp cisco X.25 service (XOT)
ellpack 2025 tcp
xribs 2025 udp
h2250-annex-g 2099 tcp H.225.0 Annex G Signalling [ITU-T] [ITU-T_TSB] 2013-01-31
h2250-annex-g 2099 udp H.225.0 Annex G Signalling [ITU-T] [ITU-T_TSB] 2013-01-31
lockstep 2125 tcp LOCKSTEP [Karl_Forster] [Karl_Forster]
lockstep 2125 udp LOCKSTEP [Karl_Forster] [Karl_Forster]
rcip-itu 2225 tcp Resource Connection Initiation Protocol [ITU_TSB] [ITU_TSB]
2225 udp Reserved
rcip-itu 2225 sctp Resource Connection Initiation Protocol [ITU_TSB] [ITU_TSB]
remote-collab 2250 tcp remote-collab [Richard_Walters] [Richard_Walters]
remote-collab 2250 udp remote-collab [Richard_Walters] [Richard_Walters]
dif-port 2251 tcp Distributed Framework Port [Sebastien_Lambla] [Sebastien_Lambla]
dif-port 2251 udp Distributed Framework Port [Sebastien_Lambla] [Sebastien_Lambla]
njenet-ssl 2252 tcp NJENET using SSL [Hans_U_Schmidt] [Hans_U_Schmidt]
njenet-ssl 2252 udp NJENET using SSL [Hans_U_Schmidt] [Hans_U_Schmidt]
dtv-chan-req 2253 tcp DTV Channel Request [Richard_Hodges] [Richard_Hodges]
dtv-chan-req 2253 udp DTV Channel Request [Richard_Hodges] [Richard_Hodges]
seispoc 2254 tcp Seismic P.O.C. Port [Robert_Reimiller] [Robert_Reimiller]
seispoc 2254 udp Seismic P.O.C. Port [Robert_Reimiller] [Robert_Reimiller]
vrtp 2255 tcp VRTP - ViRtue Transfer Protocol [Max_Fudim] [Max_Fudim]
vrtp 2255 udp VRTP - ViRtue Transfer Protocol [Max_Fudim] [Max_Fudim]
pcc-mfp 2256 tcp PCC MFP [Kunihiko_Morota] [Kunihiko_Morota] 2005-08
pcc-mfp 2256 udp PCC MFP [Kunihiko_Morota] [Kunihiko_Morota] 2005-08
simple-tx-rx 2257 tcp simple text/file transfer [Daniel_Kilsdonk] [Daniel_Kilsdonk] 2006-08
simple-tx-rx 2257 udp simple text/file transfer [Daniel_Kilsdonk] [Daniel_Kilsdonk] 2006-08
rcts 2258 tcp Rotorcraft Communications Test System [Terry_Eldridge] [Terry_Eldridge] 2006-08
rcts 2258 udp Rotorcraft Communications Test System [Terry_Eldridge] [Terry_Eldridge] 2006-08
bid-serv 2259 tcp BIF identifiers resolution service [Li_Zhiping] [Zhang_Bo] 2023-03-06
bid-serv 2259 udp BIF identifiers resolution service [Li_Zhiping] [Zhang_Bo] 2023-03-06

Contact Information

ID Name Organization Contact URI Last Updated
[Alberto_Berlen] Alberto Berlen mailto:aberlen&vnet.ibm.com
[Chris_Kerrigan] Chris Kerrigan mailto:ckerrigan&hns.com
[Chris_Stanaway] Chris Stanaway mailto:stanaway&comm.mot.com
[Daniel_Kilsdonk] Daniel Kilsdonk mailto:dan&prospeed.net 2006-08
[Dave_Simmons] Dave Simmons mailto:dsimmons&macromedia.com
[David_Ferrero] David Ferrero mailto:david&zion.com
[Desmond_Chan] Desmond Chan mailto:deschan&prismedia.com
[Donald_Eastlake] Donald Eastlake mailto:d3e3e3&gmail.com
[Eric_Peterson] Eric Peterson mailto:lcc.eric&seas.ucla.edu
[Hans_U_Schmidt] Hans U Schmidt mailto:schmidth&de.ibm.com
[IESG] IESG mailto:iesg&ietf.org
[IETF_Chair] IETF Chair IETF mailto:chair&ietf.org
[ITU-T] ITU-T mailto:tsbsg16&itu.int 2013-01-31
[ITU-T_TSB] ITU-T TSB ITU-T mailto:tsbsg16&itu.int 2013-01-31
[ITU_TSB] ITU TSB, Place des Nations, CH-1211 Geneva 20 mailto:tsbmail&itu.int 2006-06
[J_S_Greenfield] J. S. Greenfield mailto:greeny&raleigh.ibm.com
[Jeff_Burdette] Jeff Burdette mailto:support&digitalenvoy.net
[Jon_Postel] Jon Postel mailto:postel&isi.edu
[Karl_Forster] Karl Forster mailto:kforster&lockstep.com
[Keith_Thompson] Keith Thompson mailto:keith.thompson&sun.com
[Kunihiko_Morota] Kunihiko Morota mailto:morota.kunihiko&jp.panasonic.com 2005-08
[Larry_Stone] Larry Stone mailto:lcs&icad.com
[Li_Zhiping] Li Zhiping CAICT mailto:lizhiping&caict.ac.cn 2023-06-29
[Lindsay_Morris] Lindsay Morris mailto:lmorris&servergraph.com
[Max_Fudim] Max Fudim mailto:fudim&virtue3d.com
[Mohsen_Banan] Mohsen Banan mailto:mohsen&rostam.neda.com
[Peter_E_Williams] Peter E Williams mailto:peter.williams&smallworld-us.com
[Phil_Frisbie] Phil Frisbie mailto:phil.frisbie&gmail.com 2018-12-17
[Prem_Tirilok] Prem Tirilok mailto:Prem.Tirilok&tellabs.com
[Richard_Hodges] Richard Hodges mailto:rh&matriplex.com
[Richard_Walters] Richard Walters mailto:walters&cs.ucdavis.edu
[Robert_Reimiller] Robert Reimiller mailto:bob&certsoft.com
[Rudi_Martin_2] Rudi Martin mailto:Rudi.Martin&edo.mts.dec.com
[Sebastien_Lambla] Sebastien Lambla mailto:lambla&bouygtel.com
[Terry_Eldridge] Terry Eldridge mailto:Terry.Eldridge&6pointn.com 2006-08
[Walt_Modic] Walt Modic mailto:Walt.Modic&dionex.com
[Zhang_Bo] Zhang Bo CAICT mailto:zhangbo3&caict.ac.cn 2023-06-29